- #1

Monocerotis

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## Homework Statement

There are two short questions I'm absolutely stumped by. And I can't even find a way to work backwards from the answer to understand them.

Please help if you can, these two questions are driving me nuts ;__;

__Question 1)__

by applying a force you accelerate a ball upwards at 16m/s

^{2}for 0.5 seconds. How high does the ball go after you let go (from it's starting position)?

--> Answer: 5.26m

__Question 2)__

How much applied force is required to accelerate a 2.0kg ball upwards at 3.0 m/s

^{2}

--> Answer: 27N [Up]

## Homework Equations

Ref. 3.

## The Attempt at a Solution

__Question 1 Attempt__

V

_{2}= V

_{1}(Δt)+ 1/2 A

_{av}(Δt)

^{2}

V

_{2}= 0(0.5)+ 16m/s

^{2}(1/4)

V

_{2}= 4m/s

Δd = V

_{2}(Δt) - 1/2 A

_{av}(Δt)

^{2}

Δd = 4m/s(0.5s) - 1/2 16m/s(0.5s)

^{2}

Δd = 2 - 2

Δd = 0 ?????????

__Question 2 Attempt__

F

_{net1}=(m)(a)

F

_{net1}= 2.0kg(3.0m/s

^{2})

F

_{net1}= 6N

F

_{net2}= (m)(a = g)

F

_{net2}= (2.0kg)(9.8m/s

^{2})

F

_{net2}= 19.6N

F

_{net total}= 19.6 + 6

F

_{net total}= 25.6N

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